TWI530542B - Composition for forming adhesive film, adhesive film before light curing for further processing, adhesive film and electronic paper display - Google Patents

Description

Composition for forming an adhesive film, adhesive film for pre-curing, adhesive film, and electronic paper display device

The present invention provides a composition for forming an adhesive film, an adhesive film for pre-photocuring, an adhesive film, and an electronic paper display device.

In general, a digital paper display is attracting attention as a next-generation display device next to a liquid crystal display, a plasma display panel, and an organic luminescence display, and Reflective display devices were evaluated as the best ideal components.

In particular, electronic paper is a flexible substrate that can be used to display text or images by using a flexible substrate such as a thin plastic that is sprayed in an oil hole such as millions of beads, and can be played for millions of times. In the future, it is expected to be a substitute for materials such as books, newspapers, magazines, and the like. Moreover, compared with the existing flat display panels, electronic paper is cheaper to produce, does not require background illumination or continuous recharging, and can be driven with very little energy, so that energy efficiency is also significantly prioritized. At the same time, e-paper is very sharp, has a wide viewing angle, and has a memory function that does not completely disappear even without a power supply. Therefore, it is widely used in public signage, advertising, and electronics. The possibility of books, etc.

The above electronic paper may be formed by a structure including an ink layer using a solvent and laminating a sealing film on the upper portion thereof to seal the ink layer. With such a configuration, the sealing film is in contact with the solvent, and the bonding composition forming the sealing film has a chemical resistance to the solvent, and as a result, there is a problem that the high-temperature reliability and durability of the electronic paper are lowered.

An embodiment of the present invention provides a composition for forming an adhesive film which is excellent in chemical resistance to a solvent.

Still another embodiment of the present invention provides an adhesive film for pre-curing processing which is excellent in chemical resistance to a solvent.

Another embodiment of the present invention provides an adhesive film prepared from the above composition for forming an adhesive film.

Another embodiment of the present invention provides an electronic paper display device prepared by using the above adhesive film instead of using a sealing film.

An embodiment of the present invention provides a composition for forming an adhesive film comprising a phenoxy-based thermosetting resin, a cyclic epoxy-based photocurable compound, an isocyanate-based thermosetting agent, and a cationic photoinitiator.

The phenoxy-based thermosetting resin may have a glass transition temperature of from 90 ° C to 120 ° C.

The phenoxy-based thermosetting resin may have a weight average molecular weight of from 40,000 g/mol to 60,000 g/mol.

The above cyclic epoxy photocurable compound may comprise a bisphenol A type selected from In the group consisting of an epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type phenoxy resin, a bisphenol type epoxy compound, an alicyclic epoxy compound, a brominated epoxy compound, and a combination thereof At least one.

The above-mentioned cyclic epoxy-based photocurable compound may have a glass transition temperature of from 90 ° C to 120 ° C.

The cyclo-epoxy photocurable compound may be selected from the group consisting of a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type phenoxy resin, a bisphenol type epoxy compound, and an alicyclic ring. At least one of the group consisting of an oxygen compound, a brominated epoxy compound, and a combination thereof.

The content ratio of the phenoxy-based thermosetting resin and the cyclic epoxy-based photocurable compound may be from 1:1.5 to 1:2.5.

The above cationic photoinitiator may be an onium salt type ultraviolet cleavage type initiator.

The above cationic photoinitiator is contained in an amount of from 5 parts by weight to 15 parts by weight per 100 parts by weight of the above-mentioned cyclic epoxy-based photocurable compound.

The above-mentioned isocyanate-based thermosetting resin is contained in an amount of 0.1 part by weight to 1.0 part by weight based on 100 parts by weight of the above-mentioned phenoxy-based thermosetting resin.

The composition for forming an adhesive film may further comprise a component selected from the group consisting of a decane binder, an inorganic binder, a gloss agent, a wettability improver, a pigment, a deodorant, an antifoaming agent, an antioxidant, an organic flame retardant, and a thickener. At least one or more additives selected from the group consisting of plasticizers and combinations thereof.

According to still another embodiment of the present invention, the resin composition for forming an adhesive film is dried and thermally cured by heat treatment, and photocuring is added before photocuring. Use an adhesive film.

The adhesive film for pre-curing processing may be a mixture of a solidified phenoxy thermosetting resin cured product and a liquid cyclic epoxy-based photocurable compound.

The degree of curing of the above-mentioned adhesive film for photocuring may be from 95% to 98%.

The adhesive film for pre-curing processing may be in a state in which the phenoxy-based thermosetting resin in a solid state is immersed in an epoxy-based photocurable compound, and the epoxy-based photocurable compound contains a ring in the liquid main chain. .

The adhesive film for pre-curing processing described above may have a measured adhesion of 30 gf to 80 gf at a temperature of 60 ° C by a ring-shaped adhesion tester at a speed of 100 mm/min on a sus plate.

Another embodiment of the present invention provides an adhesive film prepared by subjecting the above-mentioned adhesive film for pre-curing processing to photocuring.

Another embodiment of the present invention provides an electronic paper display device comprising: an upper electrode; a lower electrode disposed opposite to the upper electrode; and an ink receiving layer disposed between the upper electrode and the lower electrode to form a partition The micro-space houses the ink inside the micro-space; and a sealing film that bonds the upper electrode and the ink-receiving layer and photo-cures the photo-curing adhesive film.

The above sealing film may be a transparent film having a thickness of 5 μm to 10 μm.

The above sealing film is immersed in a halogenated carbon solvent, a dodecane solvent or a mixed solvent thereof at a temperature of 90 ° C for 12 hours, and the elution amount of the above sealing film eluted by a halogenated carbon solvent or a dodecane solvent may be 5% by weight or less.

The contact angle of the surface of the above sealing film may be 105 or less.

The adhesive film is excellent in chemical resistance to a solvent, and an electronic paper display device to which the above-mentioned adhesive film is applied as a sealing film has high temperature reliability.

1‧‧‧Ink particles

2‧‧‧Charged ion

3‧‧‧Organic solvents

4‧‧‧Baffle

5‧‧‧Microspace

10‧‧‧Ink containment layer

20‧‧‧ sealing film

30‧‧‧Upper electrode

40‧‧‧lower electrode

100‧‧‧Electronic paper display device

Fig. 1 is a schematic cross-sectional view showing an electronic paper display device of the present invention.

Hereinafter, embodiments of the invention will be described in detail. However, this is only an exemplification, and the present invention is not limited thereto, and the present invention is defined only in accordance with the scope of the patent application scope described later.

An embodiment of the present invention provides a composition for forming an adhesive film comprising a phenoxy-based thermosetting resin, a cyclic epoxy-based photocurable compound, an isocyanate-based thermosetting agent, and a cationic photoinitiator.

The above adhesive film-forming composition can be formed of an adhesive film for pre-curing processing for bonding between elements constituting an electronic device, and the film can be formed into an adhesive film by subsequent photo-curing.

The adhesive film formed of the above-mentioned composition for forming an adhesive film preferably has high temperature reliability and chemical resistance to an organic solvent. Thus, the above adhesive film can be suitably applied to a sealing film for an electronic paper display device.

The adhesive film-forming composition contains a thermosetting resin and a photocurable compound, and a specific type of thermosetting resin and a specific type of photocurable compound are selected and combined to improve high-temperature reliability and chemical resistance to an organic solvent. Sex, and can minimize adhesion.

For the above phenoxy-based thermosetting resin, as long as it is at the junction of the compound The compound having a bisphenol structure in the structure is not particularly limited, and specifically, it may be a bisphenol A type phenoxy resin, a bisphenol F type phenoxy resin, a bisphenol AF type phenoxy resin, or a bisphenol S. Type phenoxy resin, brominated bisphenol A type phenoxy resin, brominated bisphenol F type phenoxy resin, phosphorus-containing phenoxy resin, etc., and may comprise a group selected from the group consisting of At least one.

After the phenoxy-based thermosetting resin is thermally cured, the phenoxy structure is crosslinked to form a film (corresponding to an adhesive film for pre-photocuring processing or a B-stage processed film to be described later). The phenoxy-based thermosetting resin exhibits excellent chemical resistance properties, forms a film densely crosslinked, and forms a hydrophilic film, so that even if it is exposed to an organic solvent such as a halogenated carbon, the coating film can be prevented from collapsing. phenomenon. The above characteristics can be suitably applied to a composition for forming a sealing film for an electronic paper display device of the present invention.

The phenoxy-based thermosetting resin may have a glass transition temperature of from about 90 ° C to about 120 ° C. By using a phenoxy-based thermosetting resin having a high glass transition temperature in the above range, the above-mentioned composition for forming an adhesive film can impart excellent chemical resistance to a film formed by heat treatment or heat curing.

The phenoxy-based thermosetting resin may have a weight average molecular weight of from about 40,000 g/mol to about 60,000 g/mol. When the weight average molecular weight is less than the above range, the viscosity is too low, and it is difficult to form a uniform coating film when the composition is applied, and when the sealing film in the electronic paper display device is formed, the residual volatile component is left after the heat curing. , continuous contact with the ink, and dissolution, so chemical resistance may decrease over time. Further, when it exceeds the above range, when it is consumed for a long time or forms a network structure after curing, the molecular weight between the solidification points becomes large, and the chemical resistance is lowered, and the viscosity becomes very high. When the film is coated, the thickness becomes uneven, and thus there is a possibility that the appearance quality is deteriorated.

The cycloepene photocurable compound can be a compound which can be polymerized by irradiation with ultraviolet rays or an electron beam, etc., and can be in the form of a monomer, an oligomer or a polymer, and can be used without limitation. An epoxy-based photocurable compound having a ring-shaped ring structure in the main chain.

Specifically, the cycloepene photocurable compound may be a bisphenol A epoxy compound, a bisphenol F epoxy compound, a bisphenol S phenoxy resin, a bisphenol epoxy compound, or an alicyclic ring. An epoxy compound, a brominated epoxy compound or the like, and may contain at least one selected from the group consisting of combinations thereof.

The adhesive film-forming composition is contained in a mixture with a cyclic epoxy-based photocurable compound in order to replenish physical properties that are difficult to obtain when the phenoxy-based thermosetting resin is used alone. When the phenoxy-based thermosetting resin is thermally cured to form a film, the ring-form epoxy photocurable compound is uniformly distributed between the thermally cured phenoxy-based thermosetting resins before photocuring. Gives adhesion. Thereafter, when the film is photocured, the uniformly distributed cyclic epoxy photocurable compound and a part of the phenoxy structure are cured to achieve chemical resistance.

The above-mentioned cyclic epoxy-based photocurable compound may have a glass transition temperature of from about 70 ° C to about 120 ° C. By using a cyclic epoxy-based photocurable compound having a high glass transition temperature as described above, the adhesive film formed of the above-mentioned composition for forming an adhesive film has high-temperature reliability and chemical resistance to an organic solvent, and Can minimize adhesion.

The cyclic epoxy-based photocurable compound is cured to exhibit transparency, has excellent oxidation resistance, and does not cause yellowing due to light. Therefore, it can be suitably used as a sealing film for forming an electronic paper display device. Composition, and the adhesion is minimized, and therefore, enables ink composition to be contacted with the ink composition used in the electronic paper display device The problem of the attached particles being attached is minimized.

When the ring-shaped epoxy photocurable compound is formed into a film, the contact with the hydrophobic solvent is minimized depending on the hydrophilicity, and the chemical resistance to the solvent can be improved.

The weight ratio of the phenoxy-based thermosetting resin and the cyclic epoxy-based photocurable compound may be from about 1:1.5 to about 1:2.5. The adhesive film formed of the above-mentioned adhesive film-forming composition containing a phenoxy-based thermosetting resin and a cyclic epoxy-based photocurable compound having the above content ratio exhibits excellent high-temperature reliability and preferable organic solvent. Chemical resistance while minimizing adhesion.

The composition for forming an adhesive film may be an isocyanate-based thermosetting agent as a thermosetting agent.

The above isocyanate-based thermosetting agent can be used without any limitation as long as it is a compound having an isocyanate group, and the above-mentioned isocyanate can undergo a polyurethane polymerization reaction with a hydroxyl group.

Specifically, the isocyanate group in the isocyanate-based thermosetting agent is urethane-reacted with the hydroxyl group in the phenoxy-based thermosetting resin in the composition for forming an adhesive film to crosslink the phenoxy-based thermosetting resin. The (B-stage) film before photocuring is densified, whereby film processing is easily performed.

Further, when the cyclic epoxy photocurable compound is cured, a hydroxyl group is formed, but a polyurethane polymerization reaction occurs also with the hydroxyl group as described above, whereby a denser film can be formed.

Specifically, the above isocyanate type thermosetting agent may be blocked isocyanate or isophorone diisocyanate. Alkyl diisocyanate, trifunctional isocyanate (HDI trimer), or the like, and may contain at least one selected from the group consisting of them.

The adhesive film-forming composition may contain from about 0.1 part by weight to about 1.0 part by weight of the isocyanate-based heat curing agent per 100 parts by weight of the phenoxy-based thermosetting resin. The composition for forming an adhesive film containing the isocyanate-based thermosetting agent in the above content is easy to be subjected to film processing, and the adhesive film thus prepared can impart appropriate strength.

The cationic photoinitiator absorbs light energy such as an electron beam, visible light, or ultraviolet energy to form a cation, thereby efficiently initiating an epoxy in a photopolymerization reaction.

As the above cationic photoinitiator, for example, an onium salt ultraviolet cracking type initiator can be used.

The above-mentioned onium salt type ultraviolet cleavage type initiator may specifically be a diary liodonium salt, a triaryl sulfonium salt, a triarylselenonium salt or a tetraaryl phosphorus. A tetraaryl phosphonium salt, an aryldiazonium salt, or the like, and an anthracene ultraviolet cleavage type initiator containing a ruthenium atom, a boron type ultraviolet cleavage type initiator containing a boron atom, or the like can be used.

For example, the diaryliodonium salt may be a compound represented by Y ₂ I ⁺ X ^- (Y may be an aryl group having a substituent, X ^- is a non-nucleophile or a non-basic anion) . Examples of the above non-nucleophilic or non-basic anion X ^- may include SbF ₆ ^- , SbCl ₆ ^- , BF ₄ ^- , [B(C ₆ H ₅ ) ₄ ] ^- , [B(C ₆ F ₅ ) ₄ ] ^- , [B(C ₆ H ₄ CF ₃ ) ₄ ] ^- , [(C ₆ F ₅ ) ₂ BF ₂ ] ^- , [C ₆ F ₅ BF ₃ ] ^- , [B(C ₆ H ₃ F ₂ ) ₄ ] ^- , AsF ₆ ^- , PF ₆ ^- , HSO ₄ ^- , ClO ₄ ^-, etc.

Further, a triaryl sulfonium salt, a triaryl selenonium salt, a tetraaryl phosphonium salt, and an aryl diazonium salt may correspond to Each of the above compounds of the diaryl iodinium salt. Specifically, the above compound can be used as a triarylsulfonium salt, a triaryl selenonium salt, a tetraaryl phosphonium salt, and an aryl diazonium salt. Is by Y ₃ S ⁺ X ^- , Y ₃ Se ⁺ X ^- , Y ₄ P ⁺ X ^- and YN ₂ ⁺ X ^- (Y is an aryl group which may have a substituent, and X ^- is non-nucleophilic (non-nucleophile Or a compound that is not a basic anion).

The composition for forming an adhesive film may contain from about 5 parts by weight to about 15 parts by weight of a cationic photoinitiator per 100 parts by weight of the cyclo-epoxy photocurable compound. The photopolymerization initiator maintains the above range, and further, does not generate too many molecules having a short bonding length, and the durability of the adhesive film prepared from the composition for forming an adhesive film can be ensured.

The composition for forming an adhesive film may further contain, for example, a decane binder, an inorganic binder, a gloss agent, a wettability improver, a pigment, a deodorant, an antifoaming agent, an antioxidant, and an organic resistance insofar as the inherent characteristics are not lost. Additives such as a fuel, a thickener, a plasticizer, and the like.

According to still another embodiment of the present invention, the resin composition for forming an adhesive film is dried and thermally cured by heat treatment, and a photocurable pre-curable film for photocuring can be added.

The resin composition for forming an adhesive film is applied onto the upper portion of the release film to form a coating layer, and then heat-treated to prepare an adhesive film for pre-curing.

The above heat treatment may be performed by hot air at about 110 ° C to about 130 ° C for about 3 minutes to 5 minutes.

When the release film is peeled off from the coating layer for the pre-curing adhesive film, there is no limitation as long as it can be easily removed without leaving a residual material. The above release film can be used as an example For example, a polyethylene terephthalate coated with a release agent or a wet coating of a coating layer of the adhesive film for pre-curing processing described above is coated with a fluorine release agent-containing polyethylene terephthalate. ester. Further, when the coating layer formed on the release film is heat-treated, the release film cannot be deformed with heat, and therefore, a polyimide or a poly(naphthalene) pair coated with a release agent depending on the drying temperature can also be used. Polyphthalate (polynaphthalene terephthalate) and the like.

As described above, the resin composition for forming an adhesive film is dried and thermally cured by heat treatment, whereby an adhesive film for processing before photocuring (B-stage processed film) can be formed.

The above-mentioned adhesive film for pre-curing processing is a form used in the processing step before the formation of the adhesive film layer in the electronic component to be applied.

First, by heat-treating the resin composition for forming an adhesive film to form a film, it can be used in a form that can be easily processed, and the photo-curing step can be added to the adhesive film for pre-curing, and the bonding performance can be imparted by performing additional photocuring. For example, an adhesive film can be formed in an article that can be used together with an electronic component.

The adhesive film for pre-curing processing may be in a state in which a cured product of the above-described phenoxy thermosetting resin and a cyclic epoxy-based photocurable compound in a liquid state are mixed. That is, the phenoxy thermosetting resin and the photocurable epoxy resin can efficiently produce an adhesive film for pre-curing processing at a ratio of about 1:1.5 to about 1:2.5. When the resin composition for forming an adhesive film is heat-treated, the phenoxy thermosetting resin is thermally cured to form a solid phase film, and the phenoxy thermosetting resin having such a solid phase film is uniformly distributed on the ring-shaped ring. The state (IPN: structure) of the oxygen photocurable compound can form the above-mentioned adhesive film for pre-curing processing.

The adhesive film for pre-curing processing is prepared from the above-mentioned composition for forming an adhesive film, and the degree of curing of the phenoxy-based thermosetting resin can be maximized.

The degree of curing described above means the degree of curing, and can be defined by the following calculation formula 1.

[Equation 1] Curing degree (%) = {1 - (W _{i -} W _f ) / W _i } × 100

In the above formula, W _i represents the weight before the sample obtained by shearing the cured sample with a predetermined size is immersed in the solvent, and W _f is that the sample is immersed in the solvent for a predetermined period of time, and then filtered by a filtering device. The weight of the sample left. The type of the solvent and the time during which the sample is immersed in the solvent may vary depending on the cured product to be measured.

For example, the solvent may be an alkyl acetate solvent, a ketone solvent, an aromatic solvent, a halogenated carbon oil solvent, or the like, and may be determined by determining an appropriate reference solvent. The time during which the above sample is immersed in a solvent and left to stand may be appropriately selected, and may be, for example, about 1 day to 1 week, and is not limited thereto.

The increase in the value calculated by the degree of curing may indicate that the polymer structure of the cured product densely forms a mesh.

Specifically, the degree of curing after photocuring of the above-mentioned adhesive film for photocuring may be a mixed solvent in which a halocarbon oil and a dodecane oil are mixed in a weight ratio of about 3:7 and impregnated. After 24 hours, the value obtained by the above calculation formula 1 was about 95% to 98%. As described above, since the above-mentioned adhesive film for pre-curing has a high degree of curing, the display for electronic paper can be driven, and excellent chemical resistance can be achieved.

On the other hand, the above-mentioned adhesive film for pre-curing processing can minimize the adhesion as described above, and specifically, the ring is measured by a tensile tester (manufactured by Instron Co., Ltd., model name: 4443). Adhesion. After preparing a sample of the adhesive film for pre-curing processing at a size of about 3 cm × 10 cm, the sample was placed in a chamber at about 60 ° C for about 1 hour or more, and then at a speed of 100 mm/min. The adhesion was measured by a SUS plate, and as a result, the measured value of the adhesive force measured at a temperature of about 60 ° C may be about 30 gf to 80 gf.

Another embodiment of the present invention provides an adhesive film prepared by performing photocuring on the above-mentioned adhesive film for pre-curing.

The above adhesive film is prepared from the composition for forming an adhesive film as described above, so that the hydrophilicity is very high, and the chemical resistance to a specific organic solvent is preferable.

Another embodiment of the present invention provides an electronic paper display device comprising: an upper electrode; a lower electrode disposed opposite to the upper electrode; and an ink receiving layer between the upper electrode and the lower electrode and formed by the partition The micro-spaces in which the plates are separated and the ink are accommodated in the micro-space; and a sealing film that bonds the upper electrode and the ink-receiving layer, and is formed by photocuring the above-mentioned adhesive film for pre-curing.

Fig. 1 is a schematic cross-sectional view showing the electronic paper display device of the present invention.

In the first embodiment, the sealing film 20 is bonded to the upper electrode 30 while sealing the micro-space of the ink composition in which the ink containing layer 10 is housed in the electronic paper display device 100, and is formed by the aforementioned bonding. The pre-curing adhesive film formed by the composition is formed between the ink containing layer 10 and the upper electrode 30 and then photocured.

The above photocuring can be performed, for example, by ultraviolet irradiation.

The ultraviolet curing for performing the above photocuring can be carried out for about 10 seconds to about 15 seconds with a commonly used metal halide lamp.

Light amount of the irradiated ultraviolet ray irradiation is preferably from about 0.5J / cm ² to about 2.0J / cm ^2, more preferably from about irradiated with 1.0J / cm ² to about 1.5J / cm ^2.

The upper electrode 30 and the lower electrode 40 may include, for example, an indium tin oxide electrode. to make.

The above micro space can be formed by a microcapsule or a microcup. Fig. 1 shows an electronic paper display device using a microcup 5 structure. For example, the above microcup 5 may be formed of a height of from about 15 μm to about 30 μm and a length and width of from about 5 μm to about 180 μm.

The ink containing layer 10 is arranged in the above-described micro space, and accommodates an ink composition containing the ink particles 1 and the charged particles 2 dispersed in the organic solvent 3 in the inside of the micro space.

The upper electrode 30 and the lower electrode 40 are respectively located at the upper portion and the lower portion of the micro space. When a voltage is applied, the charged particles 2 dispersed in the solvent 3 move and are arranged to reflect black and white or color.

In the micro-cup type electronic paper display device, the separator 4 is formed in order to prevent the charged particles 2 from moving in the parallel direction.

The separator 4 separates pixels and pixels and functions to maintain the space of the microcups 5 in a predetermined manner. Further, when applied to a flexible display device, the spacer 4 functions as a support for maintaining the space of the microcup 5 in a predetermined manner, and the spacer 4 does not detach from the upper electrode 30 and the lower electrode 40 even when it is bent. And to bond.

When the separator 4 is lifted off from the upper and lower indium tin oxide electrodes 30, the charged particles 2 arranged in the pixel space of each of the microcups 5 move toward the other peripheral microcups 5, and thus the image quality becomes unstable. As the pixel becomes lower, the result is an increase in the defect of the product itself.

In order to prevent the above problem from occurring, the sealing film 20 is closely attached to the upper electrode 30.

The sealing film 20 formed of the above-described composition for forming an adhesive film can closely bond the separator and the upper electrode 30, and the adhesion is preferably minimized while the bonding force is minimized. The phenomenon that the charged particles 2 are fixed to the sealing film 20 can be minimized.

Further, the sealing film 20 is in direct contact with the ink compositions 1 and 2 accommodated in the ink receiving layer 10 located at the lower portion, and the sealing film 20 is prepared from the composition for forming an adhesive film as described above. Excellent high temperature reliability and excellent chemical resistance to solvents.

The above ink composition, for example, a solvent 3 containing a halocarbon solvent or a dodecane organic solvent is often used, in particular, the above-mentioned sealing film 20 has a halogenated carbon solvent or twelve as described above. Alkane solvents have excellent chemical resistance.

The above-mentioned halogenated carbon solvent is specifically a generic term for a compound which is not hydrogen but a halogen compound which is substituted with methane, and may be a halogenated carbon oil 0.8 sold by Halocarbon Company, a halogenated carbon oil 1.8, etc., and the above dodecane The solvent may specifically be n-dodecane.

The above sealing film 20 can be formed of a transparent film having a thickness of from about 5 μm to about 10 μm. The sealing film 20 formed of the above-described thickness range can excellently seal the ink receiving layer 10 while being excellent in adhesion to the separator 4, and can be embodied as transparent.

The chemical resistance can be evaluated by measuring the elution amount of the halogenated carbon solvent or the dodecane solvent of the sealing film 20 described above. Specifically, the elution amount (X) can be obtained by the following calculation formula 2.

[Calculation Formula 2] The elution amount (X) [%] = [(the initial weight of the sealing film - the weight of the sealing film after immersing in the solvent for a predetermined time) / the initial weight of the sealing film] × 100

The solvent in the above formula may be a mixed solution of a halogenated carbon or a dodecane, and the immersion time may be, for example, about 24 hours to about 48 hours at normal temperature, and may be, for example, about 40 ° C to about 60 ° C under high temperature conditions. Dip and elute.

The elution amount (X) is an index which becomes a binder film after the binder composition is cured by ultraviolet rays, and shows the degree of chemical resistance to the halocarbon and the dodecane solvent by the crosslinking density. The more the elution amount (X) The lower the chemical resistance is, the more the above-mentioned elution amount (X) is closely related to the high-temperature durability when driving a device such as an electronic paper display device.

After the initial weight of the sealing film 20 is measured, it is immersed in a halogenated carbon solvent or a dodecane solvent which is often used as a solvent for the ink composition of the electronic paper display device for about 24 hours to about 48 hours, at 110. After drying at a temperature of ° C for about 3 hours to about 5 hours to measure the residual weight, the value of the elution amount (X) obtained by the calculation of Formula 2 may be about 5% or less. As described above, the sealing film 20 can exhibit excellent chemical resistance of about 5% or less by the amount of elution obtained by the calculation formula 2.

Further, the surface of the above-mentioned sealing film prepared from the above-mentioned composition for forming an adhesive film is photocurable with a diol hydroxyl group (-OH group) of a phenoxy structure, and the hydroxyl group generated by epoxy ring opening is hydrophilic, for example. The contact angle to water can be expressed as about 95° or less.

The embodiments and comparative examples of the present invention are described below, but the following embodiments are merely one embodiment of the present invention, and the present invention is not limited to the following embodiments.

Example 1

A phenoxy thermosetting resin having a weight average molecular weight of 52,000 g/mol and a glass transition temperature of about 94 ° C. PKHH (trade name) of Inchem Co., Ltd. was dissolved in methyl cellosolve in a 30 wt% concentration solution, and filtered at 300 mesh. A phenoxy solution (P1) was prepared. 22.0 g (in which PKHH content: 6.6 g) of the above phenoxy solution (P1) and 15.4 g of a cyclic epoxy compound were stirred and mixed with S-28 (double-(3,4-ring) of Synasia Co., Ltd. Oxycyclohexyl)adipate), 0.06 g of isocyanate curing agent MFA-75X from Asahi Kasei Co., Ltd., and 2.3 g of cationic photoinitiator UVI-6974 (Mituto (Momentive)) The company prepared a composition for forming an adhesive film by containing triarylsulfonium hexafluoro antimonite as a main component.

On the polyethylene terephthalate release film, the above composition was formed into a coating layer having a thickness of 10 μm, and then dried at a temperature of 140 ° C for 3 minutes by hot air to prepare an adhesive film for pre-curing processing. .

The adhesive film for pre-curing preparation prepared above was irradiated with a 200 mW ultraviolet curing device for 10 seconds to obtain an adhesive film. When the photocuring irradiation amount is less than 0.5 J/cm ² , the surface may remain on the surface after photocuring, and therefore the measurement is performed under the same amount of light.

Example 2

In Example 2, an adhesive film was formed in the same manner as in Example 1 except that the glass transition temperature of the phenoxy resin was changed and used.

A phenoxy thermosetting resin having a weight average molecular weight of 60,000 g/mol and a glass transition temperature of about 98 ° C. PKHH (trade name) of Inchem Co., Ltd. was dissolved in methyl cellosolve in a 30 wt% concentration solution, and filtered at 300 mesh. A phenoxy solution (P2) was prepared. 22.0 g (in which PKHH content: 6.6 g) of the above phenoxy solution (P2) and 15.4 g of a cyclic epoxy compound were stirred and mixed with S-28 (double-(3,4-ring) of Synasia Co., Ltd. Oxycyclohexyl)dipic acid), 0.06 g of an isocyanate curing agent MFA-75X from Asahi Kasei Co., Ltd., and 2.3 g of a cationic photoinitiator UVI-6974 (Momentive), including triarylsulfonium A composition for forming an adhesive film is prepared by using hexafluorosulfonium hexafluoro antimonite as a main component.

On the polyethylene terephthalate release film, the composition was formed into a coating layer having a thickness of 10 μm, and then dried at a temperature of 140 ° C for 3 minutes by hot air to prepare a paste for photocuring. conjunctiva.

The adhesive film for pre-curing preparation prepared above was irradiated with a 200 mW ultraviolet curing device for 10 seconds to obtain an adhesive film. When the photocuring irradiation amount is less than 0.5 J/cm ² , the surface may remain on the surface after photocuring, and therefore the measurement is performed under the same amount of light.

Comparative example 1

A phenoxy thermosetting resin having a weight average molecular weight of 52,000 g/mol and a glass transition temperature of 94 ° C was dissolved in methyl cellosolve by Inchem PKHH (trade name) in a 30 wt% concentration solution, and filtered at 300 mesh. A phenoxy solution (P1) was prepared. In addition to the above 22.0 g (in which PKHH content: 6.6 g), a phenoxy solution (P1), 15.4 g of triallyl isocyanate (TAIC, triallylisocyanurate, manufactured by Nippon Kasei), and 2.3 g of Functional thiol compound (trade name PEMP, pentaerythritol tetracyclic (3-mercapto-propionate)), 2.3 g of a free radical initiator Irgacure 184 (BASF) to prepare a combination for forming an adhesive film An adhesive film was formed in the same manner as in Example 1 except that the material was used. In Comparative Example 1, since PEMP was used as the photocurable compound, it was used together with a radical initiator.

Comparative example 2

The thermosetting resin was not used, except that 6.6 g of an epoxy acrylate compound (PE-210 of Mivan Specialty Chemical Co., Ltd.) and 2.3 g of a polyfunctional thiol compound (trade name, Pentaerythritol tetracyclo(3-indolyl-propionate), 15.4 g of triallyl isocyanate (TAIC, triallylisocyanurate, manufactured by Nippon Kasei), 2.3 g of free radical initiator Irgacure 184 (Basf) An adhesive film was formed in the same manner as in Example 1 except that the composition for forming an adhesive film was prepared. In Comparative Example 2, PEMP was also used as a photocurable compound, and thus it was used together with a radical initiator.

Evaluation

Experimental Example 1: Evaluation of elution amount

The adhesive films prepared in Examples 1 to 2 and Comparative Examples 1 to 2 were mixed in a mixed solvent of a halogenated carbon oil (halogenated carbon halide oil 0.8) and n-dodecane oil in a weight ratio of 3:7. After immersing for 12 hours, it was filtered through a 300-mesh sieve, and dried at 110 ° C for 3 hours, and then the weight was measured and the elution amount (X) [%] was measured by the following calculation formula 2, and is shown in Table 1.

[Calculation Formula 2] The elution amount (X) [%] = [(the initial weight of the adhesive film - the weight of the sealing film after immersion in the solvent for a predetermined time) / the initial weight of the adhesive film] × 100

Experimental Example 2: Evaluation of chemical resistance

On the adhesive films prepared in Examples 1 to 2 and Comparative Examples 1 to 2, a drop of a drop of 3:7 by weight of a halogenated carbon oil (halogenated carbonized product of a halogenated carbon oil 0.8) and a positive ten were added by a dropper. After the mixed solvent of the dialkyl oil was placed in an oven at 60 ° C for 12 hours, it was observed and evaluated whether or not it was bleed and described in Table 2. In the case where the bleeding phenomenon occurs, it indicates that the chemical resistance of the adhesive film to the halogenated carbon is lowered. That is, in the case as described above, the halogenated carbon penetrates into the cured film and the adhesive film is easily wetted and expanded by the halogenated carbon. In the display device for electronic paper, the film moistened and expanded as described above is easily separated, and after applying methyl ethyl ketone (MEK, methyl ethyl ketone), the polyester wipe used in the clean room is used (Polyester) It is not easy to take off the film when wipes) and cotton wipe. When the binder film cross-linking density is wetted and swelled by the halocarbon mixture, it is judged that the cross-linking density of the film is remarkably low, and it is judged that the chemical resistance to a specific solvent is lowered.

Experimental Example 3: Evaluation of water contact angle

On the adhesive films prepared in Examples 1 to 2 and Comparative Examples 1 to 2, a drop of distilled water was dropped by a dropper, and then a contact angle analyzer was used at room temperature (Contact angle). Analyzer) The contact angle was measured and the results are shown in Table 1.

Experimental Example 4: Evaluation of adhesion (tack)

A sample obtained by cutting the adhesive film for pre-curing preparation prepared in the above Examples 1 to 2 and Comparative Examples 1 to 2 was cut in a size of 3 cm × 10 cm, and then placed in a chamber at 60 ° C. After the hour, the adhesion was measured on a stainless steel plate (sus plate) at a speed of 100 mm/min using a loop analysis tester of the texture analysis product, and the results are shown in Table 1.

Experimental Example 5: Evaluation of adhesion

After preparing a carbon halide mixture for use in a microcup sheet of an electronic paper display device, the photocuring prepared in Examples 1 to 2 and Comparative Examples 1 to 2 was thermally laminated at 70 ° C. After laminating the pre-processing adhesive film, the photocuring conditions of Examples 1 to 2 and Comparative Examples 1 to 2 were photocured and bonded, and then the adhesion was measured by a spring gauge. The results are shown in Table 1.

Experimental Example 6: Contrast (CR) measurement evaluation

The adhesive film for pre-curing processing prepared in Examples 1 to 2 and Comparative Examples 1 to 2 and the ink-containing composition (mixture of carbon black and titania beads and a halogenated carbon solvent) were prepared by thermal lamination. The microcup sheets of Image and Materials (Imige & Material) were laminated and photocured, and then placed at 60 ° C for 24 hours, and then white was measured using Minolta's CM-3700A. (White) reflectance and black (Black) reflectivity.

The white reflectance/Black reflectance was calculated for the films prepared in Examples 1 to 2 and Comparative Examples 1 to 2, and the contrast (CR, contrast ratio) values were expressed below. in FIG. 1.

Experimental Example 7: Evaluation of high temperature reliability

With respect to the adhesive films for pre-curing processing prepared in Examples 1 to 2 and Comparative Examples 1 to 2, a display device for an electronic paper having the structure shown in Fig. 1 was prepared. The photocuring conditions of the sealing film were the same as those described in Example 1. After the display device for electronic paper was produced, after standing at a temperature of 60 ° C for 240 hours, the White/Black reflectance was measured using Minolta CM-3700A to express the contrast. After standing at a high temperature, it is determined whether there is a change in contrast. The results were evaluated according to the following criteria and the results are shown in Table 1.

<Criteria for judging the rate of change of contrast>

Good: less than 5%

Bad: 5% or more

Referring to Table 1 above, it was found that the elution amounts of Examples 1 and 2 measured were less than 5%, and the contact angle with respect to water after photocuring was within about 90°. In the case of Example 1 and Example 2, unlike the Comparative Example 1 and Comparative Example 2, the epoxy-based photocurable compound was photocured to contain a hydroxyl group and was hydrophilic, and the contact angle of the solvent with high hydrophobicity after photocuring was also observed. Has not changed much.

Further, in the case of Example 1 and Example 2, it can be understood that a phenoxy thermosetting resin having an appropriate molecular weight and a glass transition temperature is used, and a low contact angle and a solvent are shown with respect to Comparative Example 1 and Comparative Example 2. Excellent chemical resistance.

In Comparative Example 2, the photocurable epoxy-based photocurable compound was used in the same manner as in Example 1 and Example 2, and the physical property evaluation results were extremely poor. In Comparative Example 1 and Comparative Example 2, the content of the hydroxyl group was relatively decreased, and the contact angle after photocuring was large, which was severely exposed to the hydrophobic solvent, which showed extremely poor resistance to chemical evaluation of the solvent.

1‧‧‧Ink particles

2‧‧‧Charged ion

3‧‧‧Organic solvents

4‧‧‧Baffle

5‧‧‧Microspace

10‧‧‧Ink containment layer

20‧‧‧ sealing film

30‧‧‧Upper electrode

40‧‧‧lower electrode

100‧‧‧Electronic paper display device

Claims (20)

A composition for forming an adhesive film, comprising: a phenoxy-based thermosetting resin; a cyclic epoxy-based photocurable compound; an isocyanate-based thermosetting agent; and a cationic photoinitiator; wherein the phenoxy-based thermosetting agent The weight average molecular weight of the resin is from 40,000 g/mol to 60,000 g/mol. The composition for forming an adhesive film according to the above aspect of the invention, wherein the phenoxy-based thermosetting resin has a glass transition temperature of from 90 ° C to 120 ° C. The composition for forming an adhesive film according to the first aspect of the invention, wherein the phenoxy-based thermosetting resin is selected from the group consisting of bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, and double Phenol type AF phenoxy resin, bisphenol S type phenoxy resin, brominated bisphenol A type phenoxy resin, brominated bisphenol F type phenoxy resin, phosphorus-containing phenoxy resin and combinations thereof At least one of the groups. The composition for forming an adhesive film according to the above aspect of the invention, wherein the cyclic epoxy-based photocurable compound has a glass transition temperature of from 90 ° C to 120 ° C. The composition for forming an adhesive film according to the first aspect of the invention, wherein the cyclic epoxy-based photocurable compound is selected from the group consisting of a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, and a bisphenol. At least one of the group consisting of a S-type phenoxy resin, a bis-epoxy compound, an alicyclic epoxy compound, a brominated epoxy compound, and a combination thereof. The adhesive film-forming composition according to the above aspect of the invention, wherein the phenoxy The content ratio of the base thermosetting resin and the above cyclic epoxy photocurable compound is from 1:1.5 to 1:2.5. The composition for forming an adhesive film according to the above aspect of the invention, wherein the cationic photoinitiator is an onium salt ultraviolet cracking initiator. The composition for forming an adhesive film according to claim 1, wherein the cationic photoinitiator is contained in an amount of from 5 parts by weight to 15 parts by weight per 100 parts by weight of the above-mentioned cyclic epoxy-based photocurable compound. . The composition for forming an adhesive film according to the above aspect of the invention, wherein the above-mentioned phenoxy-based thermosetting resin contains 0.1 part by weight to 1.0 part by weight of the above-mentioned isocyanate-based heat curing agent. . The composition for forming an adhesive film according to claim 1, further comprising a decane-bonding agent, an inorganic binder, a glossing agent, a wettability improving agent, a pigment, a deodorant, an antifoaming agent, and an anti-corrosion agent. At least one or more additives selected from the group consisting of oxidizing agents, organic flame retardants, thickeners, plasticizers, and combinations thereof. An adhesive film for pre-curing processing, which is formed by drying and thermally curing the resin composition for forming an adhesive film according to any one of the first to tenth aspects of the invention, which can be added by heat treatment. Light curing. The adhesive film for pre-curing processing according to claim 11, wherein the cured product of the phenoxy thermosetting resin and the liquid phase of the cyclic epoxy-based photocurable compound are mixed with a solid phase. . The adhesive film for pre-curing according to claim 11, wherein the degree of curing is 95% to 98%. The adhesive film for pre-curing according to claim 11, wherein the phenoxy-based thermosetting resin in a solid phase is immersed in a liquid phase of the cyclic epoxy-based photocurable compound. . The adhesive film for pre-curing according to claim 11, wherein the sus plate is measured at a temperature of 60 ° C by a looptack tester at a speed of 100 mm/min. The measured value of the tack is 30 gf to 80 gf. An adhesive film comprising: photocuring of an adhesive film for pre-curing for processing described in claim 11 of the invention. An electronic paper display device comprising: an upper electrode; a lower electrode disposed opposite to the upper electrode; the ink receiving layer is located between the upper electrode and the lower electrode to form a micro space separated by a partition, and The inside of the micro space accommodates ink; and a sealing film which bonds the upper electrode and the ink receiving layer, and is formed by photocuring the adhesive film for pre-curing according to claim 11 of the invention. The electronic paper display device according to Item 17, wherein the sealing film is a transparent film having a thickness of 5 μm to 10 μm. The electronic paper display device according to claim 17, wherein the sealing film is immersed in a halogenated carbon solvent, a dodecane solvent or a mixed solvent thereof at a temperature of 90 ° C for 12 hours, and is made of a halogenated carbon. The elution amount of the above sealing film eluted with a solvent or a dodecane solvent was 5% by weight or less. The electronic paper display device according to claim 17, wherein the sealing film The contact angle of the surface is 105° or less.